Field of the Invention
This invention relates generally to heat treating systems for metals and other heat treatable materials and in particular to a multifunction load transport mechanism for loading, unloading, and manipulating a work load.
Background of the Invention
There are known heat treating systems that include multiple treating chambers and a transport module for transporting a work load between the multiple treating chambers. In some of the known systems, the transport module is centrally located relative to the multiple treating chambers. In those systems, the central transport module includes a loading mechanism that is adapted to rotate to any of a plurality of stations that align with a treating chamber. In another known system, the treating chambers are arrayed linearly and the transport module moves linearly on tracks between treating stations. Many of the known loading/unloading mechanisms are configured to lift and carry the load with a fork transfer mechanism. Another known loading/unloading mechanism includes a chain mechanism adapted to push or pull the load between a heating chamber and a quenching chamber.
In most of the multi-station heat treating systems, the quenching chamber is separate and stationary. The centralized transporter mechanism is functionally limited to loading and unloading workloads to and from the several treating chambers, including the quenching chamber. The transport module used in the linearly arrayed system is equipped to maintain the workload under vacuum and at temperature. A separate movable quenching chamber is provided in the linear array system as an alternative transport module. However, the movable quenching chamber is limited to the use of gas quenching. When other types of quenching media are used, the workload must be transported to the quenching chamber that is set up for the desired quenching medium. Moreover, the linear arrangement has the disadvantage of requiring complex connections for power, control, water, and gas.
Another known multi-chamber heat treating system has a centralized quenching chamber that is adapted to rotate and dock with a plurality of treating chambers. That arrangement includes a load transporter in the quenching chamber, but the chamber requires a specialized docking arrangement to permit coupling to the other chambers.
In many of the known heat treating systems, the work load is stationary inside the quenching chamber during a quenching cycle. However, the work loads are not uniform in geometry or density. Therefore, when the load is stationary in the quenching chamber, the load tends to cool nonuniformly. In other words, some parts of the load cool either more slowly or more rapidly because of the static flow patterns of the quenching medium across and through the load. Also known are vacuum heat treating furnaces that include means for rotating the work load inside the furnace either during a heating cycle or during a quenching cycle.
In view of the shortcomings of the known multi-station heat treating systems it would be desirable to have a multi-purpose load transport mechanism that is adapted for use in a centrally located quenching chamber. The chamber should be adapted to provide controlled, but easy access to the other treating chambers without complex docking arrangements. Also, the transport mechanism should be adapted for use with multiple quenching media. Further, the transport mechanism should be adapted to rotate the load within the quenching chamber.